Junctophilins: a novel family of junctional membrane complex proteins.
Journal:
Mol. Cell 2000 JulAuthors:
Takeshima H, Komazaki S, Nishi M, Iino M, Kangawa K
Abstract
Junctional complexes between the plasma membrane (PM) and endoplasmic/sarcoplasmic reticulum (ER/ SR) are a common feature of all excitable cell types and mediate cross-talk between cell surface and intracellular ion channels. We have identified the junctophilins (JPs), a novel conserved family of proteins that are components of the junctional complexes. JPs are composed of a carboxy-terminal hydrophobic segment spanning the ER/SR membrane and a remaining cytoplasmic domain that shows specific a
...[more]ffinity for the PM. In mouse, there are at least three JP subtypes: JP-1, -2, and -3. JP-2 is abundantly expressed in the heart, and mutant mice lacking JP-2 exhibited embryonic lethality. Cardiac myocytes from the mutant mice showed deficiency of the junctional membrane complexes and abnormal Ca2+ transients. Our results suggest that JPs are important components of junctional membrane complexes.[less]
Mesh Headings:
Amino Acid Motifs, Amino Acid Sequence, Animals, Base Sequence, Calcium Signaling, Cell Membrane, DNA Primers, Endoplasmic Reticulum, Male, Membrane Proteins, Mice, Mice, Inbred C57BL, Mice, Knockout, Molecular Sequence Data, Muscle, Skeletal, Myocardium, Rabbits, Sarcoplasmic Reticulum, Sequence Homology, Amino Acid, Tissue Distribution